The Synthesis Of Anionic Silicone Surfactants With Amides Bond

In this experiment, the two intermediates were prepared with γ-aminopropylmethyldiethoxysilane and hexamethyldisiloxane as raw material, succinic anhydride andmaleic anhydride as the acylating agent. The two intermediates were reacted withSodium bicarbonate to obtain two kinds of new amide-containing anionic siliconesurfactants,4-(siloxane-2-propylamino)-4-oxo-butyrate and4-(siloxane-2-propylamino)-4-oxo-butene Sodium.In this experiment, the synthesis and product purification methods were investigated.The aminopropyl trisiloxane was obtained from hexamethyldisiloxane and γ-aminopropylmethyl diethoxy silane as raw material, and the tetramethyl ammonium hydroxide pentahydrate as catalyst under anhydrous conditions. Raw material mole ratio is5:1,reflux2h at90℃, distillation0.5h at130℃. The product was washed with distilled waterfor10to15times. The yield is49.1%higher than the literature (42.8%).The4-(siloxane-2-propylamino)-4-oxo-butyrate was obtained under anhydrous conditions and nitrogenconditions, as the acylating agent succinic anhydride and maleic anhydride were reactedwith3-aminopropyl trisiloxane, raw material mole ratio is about1:1.05, as theacylating agent maleic anhydride were reacted with3-aminopropyl trisiloxane, rawmaterial mole ratio is1:1.1. Under ice-cooling, the raw material was droppedslowly and the raw material react for2h, than the mixture react for2h at roomtemperature. Excess of triethylamine added to the system, the insoluble matter precipitated.Filtered cake was washed several times with dichloromethane. The insoluble mixture ofmethylene chloride was added excess hydrochloric acid system, and stirred to produce newinsolubles. The insoluble matter was removed by filtration, distillation under reduced pressureto constant weight to give the intermediate4-(trisiloxane-2-propylamino)-4-oxo-butyric acid,and4-(trisiloxane-2-propylamino)-4-oxobutanoic acid. The yield of intermediate was96.3%.Reaction of the intermediate product with aqueous sodium bicarbonate to obtain a finalproduct.The product structure was characterized by IR and1H-NMR. The critical micelleconcentration (cmc) of the new products is between1.99×10-5mol/L and3.16×10-5mol/L. The surface tension (γcmc) is30.0mN/m. The new products have good surface activity,wettability and softness compared with conventional surfactant.